Smoking tobacco products, particularly tobacco cigarettes, having ventilated areas in the region of the tip have been suggested for a number of years. In particular, the mixing of air with the smoke passing through the filter tip was felt to give a cooler and less harsh smoke.
In recent years, more sophisticated techniques for ventilating of cigarette tips have been proposed, some of which have been made commercially available. In addition to providing a cooler and less harsh smoke, it has been found that the addition of air to the smoke passing through the filter reduces the amounts of various smoke constituents delivered to the smoker.
In general, the ventilation in the filter area can be provided by two methods, or combinations of these methods. The two methods involve perforation and the use of inherently porous materials. Thus, the plug wrap which surrounds the filter element can be perforated and perforations in registry therewith can be formed in the tipping paper which surrounds both the plug wrap and the tobacco section. Further, both the plug wrap and the tipping paper can be formed of inherently porous material. Still further, either the plug wrap or tipping can be preperforated and the other component made of an inherently porous material. Consequently, it is necessary that areas in the vicinity of the perforation not be covered with perforation-blocking adhesive. It has been found that a more even and consistent distribution of air into the smoke passing through the filter can be obtained when inherently porous materials are employed rather than perforated materials in a manner described in the referenced copending application Ser. No. 193,124.